LiveSync

LiveSync abstracts all the complexity of keeping large volumes of clients in realtime sync with one or more relational databases. While LiveSync takes care of the low-level sync, you can focus on core app functionality. 

You can power any realtime collaborative application where the source of truth for the app state is stored in the database.

Build reliable interactive applications using your preferred stack.

LiveSync's client-side Models SDK makes it simple to build live, observable data models for any frontend framework. It drastically simplifies state management, with out-of-the-box support for channel lifecycle management, change event ordering & de-duplication, mutations, and optimistic updates.

import Models from '@ably-labs/models';
import { Realtime } from 'ably';

// instantiate the library
const ably = new Realtime.Promise({ key: 'YOUR_API_KEY' });
const models = new Models({ ably });

// create a model instance
const model = models.Model('post');

// register methods
await model.$register({
  $sync: getPost,
  $update: {
    'posts': { 'update': onPostUpdated },
    'comments': { 'add': onAddComment },
  },
  $mutate: { updatePost, addComment },
});

// subscribe to live changes with optimistic updates
model.subscribe((err, post) => {
    if (err) throw err;
    // post updated!
}, { optimistic: true });

// mutate the post
const [result, confirmation] = await model.mutations.updatePost('new value');

// wait for confirmation of the change from the backend
await confirmation;

LiveSync interacts with your database through a database connector, whose only point of contact with your database is an outbox table. Through the connector, clients automatically receive relevant change events via Ably's Pub/Sub channels. Subscribers are notified of data as soon as it becomes available. There is no need to poll the server for updates.